Method of and apparatus for producing power from solar ponds

Abstract

Power is produced by a power plant using a salt-water solar pond comprising an upper wind-mixed layer, a halocline and a lower convective heat storage layer. The power plant includes a heat engine for utilizing heat present in the heat storage layer of the solar pond and a condenser, which preferably is cooled by liquid droplets. In accordance with a specific embodiment of the invention the power plant is positioned within the solar pond and a flash evaporator is used in the heat engine to produce steam which is supplied to a turbine connected to a generator, the heat depleted steam exiting from the turbine and being cooled by liquid droplets in a direct-contact condenser. The size of the droplets is selected such that the heat extracted in the condenser penetrates the majority of the liquid content of most of the droplets.

What is claimed is: 
     
       1. A heat exchanger comprising: (a) a source of liquid containing non-condensable gases;   (b) a housing for containing a heated medium;   (c) means to spray droplets of said liquid into said medium for transferring heat from the medium to the droplets and for causing the residence time of the droplets in the housing to be no greater than the time required for heat to penetrate into a major portion of the liquid content in most of the droplets thereby minimizing the release into said housing of gases contained in the droplets.   
     
     
       2. A direct contact heat exchanger according to claim 1 wherein the size of the droplets is selected such that heat in the medium in said housing penetrates into the droplets no more than about 70% of the radius of the majority of the droplets. 
     
     
       3. A direct contact heat exchanger according to claim 1 wherein said liquid is water. 
     
     
       4. A method for using a direct contact heat exchanger comprising the steps of adding to the exchanger a selected fluid in the form of condensable vapor; and spraying droplets of a liquid into said condensable vapor; the size of the droplets and their residence time in contact with the condensable vapor being selected such that the majority of the liquid content in most of the droplets absorbs heat from the vapor while minimizing the release of gases contained in the droplets. 
     
     
       5. A heat exchanger according to claim 1 wherein said means for spraying prevents the release of no more than about 30% of the gases contained in the droplets. 
     
     
       6. A heat exchanger according to claim 1 wherein said means for spraying prevents the release of no more than about 22% of the gases contained in the droplets. 
     
     
       7. A heat exchanger according to claim 1 wherein said means for spraying prevents the release of no more than about 6.5% of the gases contained in the droplets. 
     
     
       8. A method according to claim 4 wherein the size of the droplets and their residence time prevents the release of no more than about 30% of the gases in the droplets. 
     
     
       9. A method according to claim 4 wherein the size of the droplets and their residence time prevents the release of no more than about 22% of the gases in the droplets. 
     
     
       10. A method according to claim 4 wherein the size of the droplets and their residence time prevents the release of no more than about 6.5% of the gases in the droplets. 
     
     
       11. A heat exchanger comprising: (a) a source of liquid containing non-condensable gases;   (b) a housing for containing a heated medium;   (c) means for spraying droplets of said liquid into said medium for transferring heat from the medium to the droplets;   (d) said means for spraying being constructed and arranged such that the residence time of the droplets in the housing is no greater than the time required for heat to penetrate into a major portion of the liquid content in most of the droplets thereby minimizing the release into said housing of gases contained in the droplets; and   (e) wherein said heated medium is a fluid in the form of a condensable vapor.   
     
     
       12. A heat exchanger according to claim 11 wherein the size of the droplets is selected such that the heat extracted from the medium in the housing penetrates no more than about 70% of the radius of the majority of the droplets. 
     
     
       13. A heat exchanger according to claim 11 wherein said liquid is water. 
     
     
       14. A heat exchanger according to claim 11 wherein said means for spraying prevents the release of no more than about 30% of the gases contained in the droplets. 
     
     
       15. A heat exchanger according to claim 11 wherein said means for spraying prevents the release of no more than about 22% of the gases contained in the droplets. 
     
     
       16. A heat exchanger according to claim 11 wherein said means for spraying prevents the release of no more than about 6.5% of the gases contained in the droplets. 
     
     
       17. A method for using a heat exchanger containing a heated fluid comprising the step of spraying into said fluid, liquid droplets of said selected fluid for vaporizing liquid from the droplets, the size of the droplets and their residence time in said heat exchanger being selected such that the percentage of liquid in the droplets which vaporizes is much greater than the percentage of gases released from the droplets. 
     
     
       18. A method according to claim 17 wherein the size of the droplets and their residence time prevents the release of no more than about 30% of the gases in the droplets. 
     
     
       19. A method according to claim 17 wherein the size of the droplets and their residence time prevents the release of no more than about 22% of the gases in the droplets. 
     
     
       20. A method according to claim 17 wherein the size of the droplets and their residence time prevents the release of no more than about 6.5% of the gases in the droplets.